Semiconductor devices are used in a variety of electronic and other applications. Well-defined and highly stable oxide and metal structures are important for the fabrication of semiconductor devices. A particularly useful oxide structure is a buried oxide (BOX) structure which is an oxide structure within a semiconductor substrate. BOX structures can be used as isolation layers and etch stops, for example. A common substrate for the formation of BOX structures is a silicon-on-insulator (SOI) wafer. SOI wafers have a BOX layer sandwiched between semiconductor layers, but have a high manufacturing cost due to additional wafer processing such as separation by implantation of oxygen (SIMOX) or Smart Cut processes.